Re: [Exim] Please add support for ACLs run at _start_ of dat…

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Author: Andreas Metzler
Date:  
To: exim-users
CC: Steinar H. Gunderson, 237947
Subject: Re: [Exim] Please add support for ACLs run at _start_ of data
On 2004-03-15 Edgar Lovecraft <exim-list@???> wrote:
> Andreas Metzler wrote:
> ..[snip]...
> > > Why?? All that really needs to be done to is to change HOW you are
> > > doing the sender callouts.
> > [...]


> > I think[1] you are missing the point. - Steinar is not concerned about
> > /his/ callouts but the callouts other machines will make to his exim
> > and these are not under his control.
> >               cu andreas
> > [1] I am not 100% sure but I cannot see how greylisting can have an
> > effect on callouts /issued/ by this machine that s using greylisting.


> Okay, perhaps I am missing something in regards to the entire greylisting
> thing (and yes I have read the papers).


[...]

I think this is correct.

> Other than possibly delaying email for longer than necessary, this would
> not be a problem even from a callout setup,


Afaict delaying email for longer than necessary is the problem:
* Both host doing greylisting with callouts: delay is doubled.
* client is doing greylisting, server is doing callbacks: People on
the server suffer greylisting delays (because the callback is
greylisted) although they don't want it. Introducing greylisting on
client suddenly delays *sending* instead of *receiving*.

[...]
> As to rejecting at the start of the DATA session, exim does this now as
> long as ALL recipients have been either rejected, defered, or discarded
> BEFORE the data command is issued by the CLIENT:
> '503 valid RCPT command must precede DATA', and in a greylisting approach,
> are not ALL of the recipients for a given message defered, denied, or
> discarded??

[...]

This DATA rejection happens in *addition* to the RCPT rejection and
therefore does not help at all in this respect. - Steinar wanted to
*accept* to stop the RCPT double-delays.
              cu andreas
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